Causes the Collector to use the breakpoint table left by the
    previous collection run when it is appending test coverage data
    to an existing performance data file. If such a breakpoint table
    exists, the node specifications are ignored. Also causes the
    Collector to write a table of test coverage breakpoint locations
    not yet covered (or not yet covered n times if /UNTIL:n is
    specified) to the data file at the end of the current collection
    run.

    This qualifier causes test coverage to be measured only once
    (or only n times for /UNTIL:n) for an entire set of collection
    runs. If a program location has been found to be covered in
    one collection run, the Collector makes no attempt to measure
    coverage of that location in any subsequent collection run. Use
    of the /PREVIOUS qualifier makes data collection more efficient,
    but you lose the ability to determine what individual collection
    runs covered which program locations. If you use the /PREVIOUS
    qualifier, you should use the /APPEND qualifier on the SET
    DATAFILE command.